|
| 1 | +import copy |
| 2 | +import random |
| 3 | +from typing import Optional, Tuple |
| 4 | + |
| 5 | +import torch |
| 6 | +import torch.nn as nn |
| 7 | +import torch.nn.functional as t_func |
| 8 | +from torch.nn.modules.utils import consume_prefix_in_state_dict_if_present |
| 9 | + |
| 10 | + |
| 11 | +class Hubert(nn.Module): |
| 12 | + def __init__(self, num_label_embeddings: int = 100, mask: bool = True): |
| 13 | + super().__init__() |
| 14 | + self._mask = mask |
| 15 | + self.feature_extractor = FeatureExtractor() |
| 16 | + self.feature_projection = FeatureProjection() |
| 17 | + self.positional_embedding = PositionalConvEmbedding() |
| 18 | + self.norm = nn.LayerNorm(768) |
| 19 | + self.dropout = nn.Dropout(0.1) |
| 20 | + self.encoder = TransformerEncoder( |
| 21 | + nn.TransformerEncoderLayer( |
| 22 | + 768, 12, 3072, activation="gelu", batch_first=True |
| 23 | + ), |
| 24 | + 12, |
| 25 | + ) |
| 26 | + self.proj = nn.Linear(768, 256) |
| 27 | + |
| 28 | + self.masked_spec_embed = nn.Parameter(torch.FloatTensor(768).uniform_()) |
| 29 | + self.label_embedding = nn.Embedding(num_label_embeddings, 256) |
| 30 | + |
| 31 | + def mask(self, x: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]: |
| 32 | + mask = None |
| 33 | + if self.training and self._mask: |
| 34 | + mask = _compute_mask((x.size(0), x.size(1)), 0.8, 10, x.device, 2) |
| 35 | + x[mask] = self.masked_spec_embed.to(x.dtype) |
| 36 | + return x, mask |
| 37 | + |
| 38 | + def encode( |
| 39 | + self, x: torch.Tensor, layer: Optional[int] = None |
| 40 | + ) -> Tuple[torch.Tensor, torch.Tensor]: |
| 41 | + x = self.feature_extractor(x) |
| 42 | + x = self.feature_projection(x.transpose(1, 2)) |
| 43 | + x, mask = self.mask(x) |
| 44 | + x = x + self.positional_embedding(x) |
| 45 | + x = self.dropout(self.norm(x)) |
| 46 | + x = self.encoder(x, output_layer=layer) |
| 47 | + return x, mask |
| 48 | + |
| 49 | + def logits(self, x: torch.Tensor) -> torch.Tensor: |
| 50 | + logits = torch.cosine_similarity( |
| 51 | + x.unsqueeze(2), |
| 52 | + self.label_embedding.weight.unsqueeze(0).unsqueeze(0), |
| 53 | + dim=-1, |
| 54 | + ) |
| 55 | + return logits / 0.1 |
| 56 | + |
| 57 | + def forward(self, x: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]: |
| 58 | + x, mask = self.encode(x) |
| 59 | + x = self.proj(x) |
| 60 | + logits = self.logits(x) |
| 61 | + return logits, mask |
| 62 | + |
| 63 | + |
| 64 | +class HubertSoft(Hubert): |
| 65 | + def __init__(self): |
| 66 | + super().__init__() |
| 67 | + |
| 68 | + @torch.inference_mode() |
| 69 | + def units(self, wav: torch.Tensor) -> torch.Tensor: |
| 70 | + wav = t_func.pad(wav, ((400 - 320) // 2, (400 - 320) // 2)) |
| 71 | + x, _ = self.encode(wav) |
| 72 | + return self.proj(x) |
| 73 | + |
| 74 | + |
| 75 | +class FeatureExtractor(nn.Module): |
| 76 | + def __init__(self): |
| 77 | + super().__init__() |
| 78 | + self.conv0 = nn.Conv1d(1, 512, 10, 5, bias=False) |
| 79 | + self.norm0 = nn.GroupNorm(512, 512) |
| 80 | + self.conv1 = nn.Conv1d(512, 512, 3, 2, bias=False) |
| 81 | + self.conv2 = nn.Conv1d(512, 512, 3, 2, bias=False) |
| 82 | + self.conv3 = nn.Conv1d(512, 512, 3, 2, bias=False) |
| 83 | + self.conv4 = nn.Conv1d(512, 512, 3, 2, bias=False) |
| 84 | + self.conv5 = nn.Conv1d(512, 512, 2, 2, bias=False) |
| 85 | + self.conv6 = nn.Conv1d(512, 512, 2, 2, bias=False) |
| 86 | + |
| 87 | + def forward(self, x: torch.Tensor) -> torch.Tensor: |
| 88 | + x = t_func.gelu(self.norm0(self.conv0(x))) |
| 89 | + x = t_func.gelu(self.conv1(x)) |
| 90 | + x = t_func.gelu(self.conv2(x)) |
| 91 | + x = t_func.gelu(self.conv3(x)) |
| 92 | + x = t_func.gelu(self.conv4(x)) |
| 93 | + x = t_func.gelu(self.conv5(x)) |
| 94 | + x = t_func.gelu(self.conv6(x)) |
| 95 | + return x |
| 96 | + |
| 97 | + |
| 98 | +class FeatureProjection(nn.Module): |
| 99 | + def __init__(self): |
| 100 | + super().__init__() |
| 101 | + self.norm = nn.LayerNorm(512) |
| 102 | + self.projection = nn.Linear(512, 768) |
| 103 | + self.dropout = nn.Dropout(0.1) |
| 104 | + |
| 105 | + def forward(self, x: torch.Tensor) -> torch.Tensor: |
| 106 | + x = self.norm(x) |
| 107 | + x = self.projection(x) |
| 108 | + x = self.dropout(x) |
| 109 | + return x |
| 110 | + |
| 111 | + |
| 112 | +class PositionalConvEmbedding(nn.Module): |
| 113 | + def __init__(self): |
| 114 | + super().__init__() |
| 115 | + self.conv = nn.Conv1d( |
| 116 | + 768, |
| 117 | + 768, |
| 118 | + kernel_size=128, |
| 119 | + padding=128 // 2, |
| 120 | + groups=16, |
| 121 | + ) |
| 122 | + self.conv = nn.utils.weight_norm(self.conv, name="weight", dim=2) |
| 123 | + |
| 124 | + def forward(self, x: torch.Tensor) -> torch.Tensor: |
| 125 | + x = self.conv(x.transpose(1, 2)) |
| 126 | + x = t_func.gelu(x[:, :, :-1]) |
| 127 | + return x.transpose(1, 2) |
| 128 | + |
| 129 | + |
| 130 | +class TransformerEncoder(nn.Module): |
| 131 | + def __init__( |
| 132 | + self, encoder_layer: nn.TransformerEncoderLayer, num_layers: int |
| 133 | + ) -> None: |
| 134 | + super(TransformerEncoder, self).__init__() |
| 135 | + self.layers = nn.ModuleList( |
| 136 | + [copy.deepcopy(encoder_layer) for _ in range(num_layers)] |
| 137 | + ) |
| 138 | + self.num_layers = num_layers |
| 139 | + |
| 140 | + def forward( |
| 141 | + self, |
| 142 | + src: torch.Tensor, |
| 143 | + mask: torch.Tensor = None, |
| 144 | + src_key_padding_mask: torch.Tensor = None, |
| 145 | + output_layer: Optional[int] = None, |
| 146 | + ) -> torch.Tensor: |
| 147 | + output = src |
| 148 | + for layer in self.layers[:output_layer]: |
| 149 | + output = layer( |
| 150 | + output, src_mask=mask, src_key_padding_mask=src_key_padding_mask |
| 151 | + ) |
| 152 | + return output |
| 153 | + |
| 154 | + |
| 155 | +def _compute_mask( |
| 156 | + shape: Tuple[int, int], |
| 157 | + mask_prob: float, |
| 158 | + mask_length: int, |
| 159 | + device: torch.device, |
| 160 | + min_masks: int = 0, |
| 161 | +) -> torch.Tensor: |
| 162 | + batch_size, sequence_length = shape |
| 163 | + |
| 164 | + if mask_length < 1: |
| 165 | + raise ValueError("`mask_length` has to be bigger than 0.") |
| 166 | + |
| 167 | + if mask_length > sequence_length: |
| 168 | + raise ValueError( |
| 169 | + f"`mask_length` has to be smaller than `sequence_length`, but got `mask_length`: {mask_length} and `sequence_length`: {sequence_length}`" |
| 170 | + ) |
| 171 | + |
| 172 | + # compute number of masked spans in batch |
| 173 | + num_masked_spans = int(mask_prob * sequence_length / mask_length + random.random()) |
| 174 | + num_masked_spans = max(num_masked_spans, min_masks) |
| 175 | + |
| 176 | + # make sure num masked indices <= sequence_length |
| 177 | + if num_masked_spans * mask_length > sequence_length: |
| 178 | + num_masked_spans = sequence_length // mask_length |
| 179 | + |
| 180 | + # SpecAugment mask to fill |
| 181 | + mask = torch.zeros((batch_size, sequence_length), device=device, dtype=torch.bool) |
| 182 | + |
| 183 | + # uniform distribution to sample from, make sure that offset samples are < sequence_length |
| 184 | + uniform_dist = torch.ones( |
| 185 | + (batch_size, sequence_length - (mask_length - 1)), device=device |
| 186 | + ) |
| 187 | + |
| 188 | + # get random indices to mask |
| 189 | + mask_indices = torch.multinomial(uniform_dist, num_masked_spans) |
| 190 | + |
| 191 | + # expand masked indices to masked spans |
| 192 | + mask_indices = ( |
| 193 | + mask_indices.unsqueeze(dim=-1) |
| 194 | + .expand((batch_size, num_masked_spans, mask_length)) |
| 195 | + .reshape(batch_size, num_masked_spans * mask_length) |
| 196 | + ) |
| 197 | + offsets = ( |
| 198 | + torch.arange(mask_length, device=device)[None, None, :] |
| 199 | + .expand((batch_size, num_masked_spans, mask_length)) |
| 200 | + .reshape(batch_size, num_masked_spans * mask_length) |
| 201 | + ) |
| 202 | + mask_idxs = mask_indices + offsets |
| 203 | + |
| 204 | + # scatter indices to mask |
| 205 | + mask = mask.scatter(1, mask_idxs, True) |
| 206 | + |
| 207 | + return mask |
| 208 | + |
| 209 | + |
| 210 | +def hubert_soft( |
| 211 | + path: str, |
| 212 | +) -> HubertSoft: |
| 213 | + r"""HuBERT-Soft from `"A Comparison of Discrete and Soft Speech Units for Improved Voice Conversion"`. |
| 214 | + Args: |
| 215 | + path (str): path of a pretrained model |
| 216 | + """ |
| 217 | + hubert = HubertSoft() |
| 218 | + checkpoint = torch.load(path) |
| 219 | + consume_prefix_in_state_dict_if_present(checkpoint, "module.") |
| 220 | + hubert.load_state_dict(checkpoint) |
| 221 | + hubert.eval() |
| 222 | + return hubert |
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